Electronic fuel tank fill limit control
AssigneeStant Manufacturing Inc.
InventorJeffrey Devall
Life of this patent
Estimating the term…
Abstract
A vent apparatus is opened to allow free flow of fuel vapor from a vehicle fuel tank through the vent apparatus to a fuel vapor recovery canister during tank refueling until a predetermined level of liquid fuel is reached in the vent apparatus. Once refueling has been completed, the vent apparatus is closed to block or limit further flow of liquid fuel to the vent apparatus. At the same time, fuel vapor discharge passageways in the vent apparatus that had been closed once the fuel tank had been filled to a predetermined capacity with liquid fuel are reopened so that fuel vapor can flow freely from the fuel tank to the canister even though the volume or height of liquid fuel in the fuel tank has not decreased since the tank was filled during refueling.
Claims20
A vent apparatus to be located in a fuel tank to regulate discharge of fuel vapor from the tank to a destination outside of the tank, the vent apparatus comprising
- a fill-limit vent valve adapted to be mounted in the tank and having a venting outlet adapted to be connected to a vent outlet of the tank and a flow port,
- the fill-limit vent valve bring responsive to fuel level in the tank to open and allow venting of vapor in the fuel tank through the venting outlet until a predetermined liquid fuel level in the fill-limit vent valve is reached,
- a control valve connected to the flow port of the fill-limit vent valve and having a fuel port receiving fuel from the tank and a drain port draining fuel, and
- an actuator coupled to the control valve to provide a first control signal causing the solenoid-controlled valve to move to a fuel-delivery position during refueling of the fuel tank to block the drain port and to open the fuel port to deliver liquid fuel from the tank to the fill-limit vent valve module allowing discharge of tank fuel vapor from a vapor space in the tank to the fill-limit vent valve module until the fuel level closes the fill-limit vent valve, and to provide a second control signal after refueling causing the control valve to move to a fuel-shutoff position to block further flow of liquid fuel from the fuel tank to the fill-limit vent valve module and to open the drain port to drain liquid fuel from the fill-limit vent valve module into the fuel tank to allow the fill-limit vent valve to open.
A vent apparatus to be located in a fuel tank to regulate discharge of fuel vapor from the tank to a destination outside of the tank, the vent apparatus comprising
- a fill-limit vent valve adapted to be mounted in the tank and having a venting outlet adapted to be connected to a vent outlet of the tank and a flow port,
- the fill-limit vent valve bring responsive to fuel level in the tank to open and allow venting of vapor in the fuel tank through the venting outlet until a predetermined liquid fuel level in the fill-limit vent valve is reached,
- a solenoid-controlled valve connected to the flow port of the fill-limit vent valve and having a fuel port receiving fuel from the tank and a drain port draining fuel,
- a pump connected to the drain port of the solenoid-controlled valve draining fuel when turned on, and
- an actuator coupled to the solenoid-controlled valve to provide a first control signal causing the solenoid-controlled valve to move to a fuel-delivery position during refueling of the fuel tank to block the drain port and to open the fuel port to deliver liquid fuel from the tank to the fill-limit vent valve module allowing discharge of tank fuel vapor from a vapor space in the tank to the fill-limit vent valve module until the fuel level closes the fill-limit vent valve, to provide a second control signal after refueling causing the solenoid-controlled valve to move to a fuel-shutoff position to block further flow of liquid fuel from the fuel tank to the fill-limit vent valve module and to open the drain port to drain liquid fuel from the fill-limit vent valve module into the fuel tank to allow the fill-limit vent valve to open, and to provide a third control signal after refueling turning on the fuel drainage pump to drain liquid fuel from the fill-limit vent valve module.
A method of controlling a vent apparatus located in a fuel tank to regulate discharge of fuel vapor from the tank to a destination outside of the tank, the method comprising
- providing flow of liquid fuel to the vent apparatus during tank refueling to operate the vent apparatus allowing flow of fuel vapor from the fuel tank through the vent apparatus to the destination until a predetermined fluid level is reach in the vent apparatus which stops the flow of fuel vapors through the vent apparatus,
- determining that refueling has been completed,
- stopping the flow of liquid fuel to the vent apparatus during tank after determining that refueling has been completed to block further flow of liquid fuel to the vent apparatus, and
- draining liquid fuel from the vent apparatus after determining that refueling has been completed to operate the vent apparatus allowing flow of fuel vapor from the fuel tank through the vent apparatus to the destination.
Dependencies are inferred from the claim text.